What this MCCB is and what it protects
The Siemens 3VA2463-8JQ32-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 630 A at 40 °C, with a breaking capacity of 440 kA at 240 V AC — that figure drops to 330 kA at 415 V and 52.5 kA at 690 V, so the interrupting rating you need to coordinate with depends on your system voltage. Three poles, rated insulation voltage 800 V, and a maximum power loss of 162 W that you'll need to account for in enclosure thermal calculations.
Ratings that decide the fit
The headline 630 A continuous rating at 40 °C is the starting point, but this breaker derates linearly as ambient temperature rises: 600 A at 45 °C, 570 A at 50 °C, all the way down to 450 A at 70 °C. If your panel runs hot — say 50 °C inside — you're effectively working with a 570 A breaker, not 630 A. The adjustable thermal-magnetic trip unit has a minimum setting of 945 A and a maximum of 5 670 A for short-circuit protection, with an initial value of 126 A for the thermal element. No undervoltage release or trip indicator fitted on this variant, but it does include ground-fault monitoring via summation current formation on the L-conductor.
Communication and integration
This MCCB includes a communication function, meaning it can report status and accept remote commands over a bus system — critical for a modern distribution panel where you want load shedding or remote trip indication. The dimensions are 248 mm high, 138 mm wide, and 110 mm deep; it mounts on a standard DIN rail or directly to a backplate. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C.